Storm Australian Severe Weather Forum
Severe Weather Discussion => General Weather - all topics not current severe weather. => Topic started by: Mike on 13 March 2007, 07:07:54 AM
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I would presume that some of the more experienced chasers use laptops and wireless internet for radar signatures and the like. Do you chasers use the Google map overlay in conjunction with the BOM radar images when chasing or is it a case of you're familiar with the areas and use visual observations when chasing?
Mike
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There are many preferences and it's not a matter of grouping new chasers of experienced chasers into any categories. People are influenced by what technology they have had access to while learning storm chasing, what technology they have access to now, and ultimately how well they can read they sky.
Some of the experienced chasers access radar either on their laptops or straight off the mobile phone most of the time on chase, others do not look at all, but may phone a friend for a radar update.
I'm not aware of anyone using Google map overlays with radar while in the field (in Australia). You soon get to know the areas you chase, relative to satellite and radar images.
Regards, Michael
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So what do I do? If storms have already formed then I'm watching radar from home then just head out asap and read the sky as to which cells to chase or not from there. Sometimes a radar update is helpful if the earlier stuff dies off or you get stuck in a rain area and want to know if there's anything else worth chasing before calling it quits.
On days when nothing has formed and I have head off based on my forecast of storms, then it is really a matter of finding good lookouts and watching and observing everything. On these days it is handy to get some satpic or radar info off someone else - or your own laptop and wireless connection if you are with someone who has that :) - when waiting for development. Visible satpics are good at showing where the cumulus fields are, or dominating cumulus and boundaries. Obviously radar coverage is pathetic in some areas so you can't use that all the time.
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I don't categorise people into 'them' and 'us' scenarios. That's just not my personality. That's why i posed the question as to what experienced chasers use - ie chasers with many years experience. Just because there are some who are not as 'experienced' does not mean that i inferred that they don't have access to technology - that's speculation and I dont do that! :)
No harm done.
Nice if you've got a vantage point to view from. Not many mountains or ranges up here - tis all flat! Radar is a bit hit and miss, I've certainly found that out this week!
Mike
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My philosphy for many years has been that anyone that chases with radar will miss a lot of the action. And despite the 'us' or 'them' mentality, the truth is in the pudding. There are experienced chasers that use radar - good luck to them. For consistency, you have to know what you are looking for - that is where the experience really lies. As Tim Marshall once said, "I like to read the skies." Results will come if you can choose a feasible target and ammend if/when necessary. In my opinion, there are only a handful that I put into this category and most are on this forum.
Admittadly, I am getting slightly lazy in terms of calling for radar. But my resonaing is since I do too much chasing, I don't want to remain out there for crap wasting my time. The last chase I did, I was able to verify my initial feelings that bugger all was going to happen even with 2000 CAPE! Sure I hung around - just in case. Wasted time.
Regards,
Jimmy Deguara
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Indeed Jimmy. Unfortunately some pick up on things faster than others and 'in the field' experience is invaluable. I have to be a radar chaser initially while i get more technical expertise and I'm trying not to rely on them too much as even now i've found i'm wasting a lot of time chasing an image that just isn't there when i get there.
But in any event I'm getting a handle on how to read the skies and I know what to look for - it's just the radar gives me some verification to assist me. Up here all i really have to do is sit at home and wait, as they'll come around us or over us eventually, but I don't want to do that - i want to be out there verbalising all the things i've learnt on the forum and knowing that what i'm observing and interpreting is paying off.
I know i'm missing out on the good stuff because my window of opportunity is relatively short with these buggers up here - if you head out too late you'll get rain, if you head out too early you'll pay the price of chasing your tail as you relied on radar and not visually.
Frustrating and annoying wasting petrol but I know that if i apply what I read here and what is in my reference books i've made then things will pay off with patience and correct observation.
Mike
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So really what other information can one obtain? You have the soundings in the morning which give you an estimate of what could occur if things stay the same - but things do change, you have your observation techniques and you books. That's all one could ask for while gaining the experience i would suspect.
I reckon what i will do is take all my bookwork with me. Sit in the car and watch the storms roll past and study the books. Have the camera handy in case there's something worth taking, but for once go out and chase but study the storms in detail and take notes!
That's probably good medicine.
Mike
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Mike,
Michael Bath and I began chasing locally in 1993. I even wrote a report at the time to ensure that we were thinking along the lines of safety. But back then, we had no internet and nobody else to turn to! Just our limited knowledge and a fax service thanks to Michael for synoptic charts and satellite imagery. We were even excited with those! How things have changed over the years. The key to distance chasing really came down to models becoming available. As suggested in another thread, once I found the then AVN model links (GFS now) and began to test it, we were within months able to travel abroad like 6 hour drives! Beyond the horizon chasing. The level of experience simply increased immensely. Some other chasers pretended to act cautiously but I know now are using the same resources.
So that is the key chase locally and then if you feel confident, chase further abroad if you feel for whatever reasoning something may occur with a high confidence level. Of course you have busts - we all did at some stage and depending on how you approach your chasing and patience, you will in the future. Busts are an invaluable source of learning - what not to do in future! David Croan even had an email address with bust in it:) Busts certainly stick in your mind.
As to the theory, there are so many resources available today that makes any person just read up and simply chase. Of course, the test is really getting out there and doing it - with safety. Learn from your mistakes, and certainly develop an understanding of what happens. If you don't have the best memory, write things down as to what you have learned or experienced.
Most of all, be happy with what you have achieved and try not comparing and especially competing with others. Friendly rivalry should remain at just that. With the explosion of storm chasing in Australia, there has been too much competition and rivalry which unfortunately has lead to incorrect reporting (too many supercells and tornadoes reported). This has spread to new and upcoming chasers. This forum hopefully will act as some form of barrier to incorrect reporting and to reinforce the achievements of one's chasing.
If you are not confident in understanding what you are doing, feel free to chase with more experienced chasers or to use a forum such as this as an educational tool.
Regards,
Jimmy Deguara
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No argument there. I have plenty of confidence going out on my own and i've always harped on safety anyway! There's been lots of times i just won't get out of the car! The forum members' answers, comments and advice as well as info from reliable sources are on paper and in the mind. I don't mind my own company actually so it's quite enjoyable to chase on my own without doing anything stupid - too old and wise for that! Better to err on the side of caution and rely on my own commonsense in this situation -
The forum definately, absolutely, positively has given me a more mature (if that's possible at 45), educated outlook and now a definite passion in something that I never realised would be so much more interesting and enjoyable than ever!!!!
What more can i say!!!
With GFS models, where do i go and what would you recommend i look at and study?
Mike
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I have another question to pose for members re chasing: I have a handle on the Skew-t diagrams, but what i'm wanting to know is when you lot are chasing do you look at the sounding charts to find out in which direction storms will go with regards to storm direction - i guess dependant on what levels do you look for wind? Do you use satpics current to see where the cells are growing and most likely to go to and how can you determine from an early date what is likely to occur that day?
Mike
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Mike,
In regards to GFS models, please read up on chase reports I/we have done in the past to get a handle of what decisions are made. To provide an explanation here requires a hell of a lot of time as there are ample scenarios to cover.
As to satellite pictures being used, you are right on the money. I refer to that noth here and the US. Soundings I sledom use because by the time they are out a decision to head out must be made and usually with longer distance chases, I am usually already 2 to 3 hours on the way to the target.
Regards,
Jimmy Deguara
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Would be nice to have that much time to get a head start on things! I've found some info re storm direction with current winds and STM so i'll look at those.
Can I ask, have you ever used a Met compass in any of your chasing as a tool?
Mike
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I certainly use a compass from time to time when in new areas to make sure the direction I think I'm facing is correct. Even in the familiar spots it's sometimes good to check the direction of the storm, so you can observe which way it is moving. It then helps to plan your next move (or not).
MB
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And what about meteorological compasses? Have you ever used them when observing the charts or would that be something you'd only use for a reference starting point before heading out?
Mike
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Wasn't sure what it was till I looked it up just then. Don't really take much notice of that info apart from what is used on soundings.
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Yes, the soundings we get from Brissy HQ only have a condensed list of indices, whereas if you get the one straight from Wyoming (only because Brissy is down) you get a whole gammit of indices - a whole page of numbers and abbreviations and quite interesting actually - but I was looking for code STM (storm motion) but none of the sounding indices for Oz have that on the sounding - wind indices are an added thing on US Skew-ts.
They give two sets of numbers, the direction the storm(s) are heading or likely to head and the speed in knots (ie: 175/30) 175 being SSE at 30kts. There's no actual skew-t chart given, but lots of listed figures - i thought that perhaps the abbr 'DRCT deg' would be the wind direction as none of the figures go past 360 degrees for the Met compass which they would use. Also they have an abbr of 'SKNT knot' which i presume is 'speed in knots' for wind? Most of the wind speeds are from 0 to 39 which seem to me to be about right considering past Skew-t graphs i've seen of late for Darwin.
Now i've just gotten a sounding with it....now HGHT is obviously distance in metres.....(looking, looking...)...upper level max at 16600m is 32kts and with a DRCT number of 90 which equates to 32/90 and comparing that to the Skew-T and we have - whala! - wind barb facing east with the right amount of barbs and to confirm 500mb area....0/9 - barb is north at 9 kts.
Phew! Now those reading this have to remember that I did not have a Skew-T plot until later to confirm the wind barbs, so this is a running lesson for myself with just figures.
As you can see that's why I was after the storm motion wind direction - but thinking that our storms are driven by the mid levels then that's perhaps where i should look. (long winded but I've just educated myself...)
Mike
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I got this when searching for meteorological compass, hence my comments above:
http://www.theweatherprediction.com/basic/obs/
What references are you using Mike ?
I use the average of wind speeds and directions between 700 and 500 hPa to estimate which way storms will head.
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Yes, agree to both. That's where I got the compass from it's Jeff Haby's site. As my longwinded post last time confirmed without having the Skew-T sounding graph and only listed indices in figures and abbreviations I was able to work out the 500-700mb winds as 0/9 and 340/6 and once i got the actual sounding skew-t i was right when viewing the barbs.
I references i used were PRES hpa, HGHT m, DRCT deg, and SKNT knot. The pages I got without the skew-t are actually all the indices in written form!
Is that what you wanted to know? :P
Mike
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Yep :) just didn't know the connection between meteorological compass and all the variables you can get off the soundings site.
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So by looking for steering winds at todays Darwin skew-t sounding at the 700-500mb region winds range from 700NE, 600NW to 500N between 6-0-8kt respectively - from the radar (to confirm) there is convection coming from the NW to the SE across Darwin and looking out the window the clouds are moving slow, which confirms the steering winds are right on track this arvo.
Mike
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As i didn't chase last night due to studying the books, everything that I've learnt from this topic confirmed the soundings at around 9pm when there was a nice storm off the coast to our NE (10 minute drive) which was the only one on radar with any substance and missed out on because I relied perhaps too much on the radar images earlier on when I should have been out in that direction looking to the horizon for some activity - which as it happens did eventuate! The lesson continues!
Mike
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For those wanting to extend their knowledge of meteorology in general should include the following link as part of their resources:
http://ww2010.atmos.uiuc.edu/(Gh)/home.rxml
It is very comprehensive and reading it is not so tedious.
Regards,
Jimmy Deguara
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Thanks for the link - very informative. Certainly a lot of material to study and excellent educational tools also. will certainly add that to my list of resource avenues.
Mike
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Satpics: I'm endeavouring not to rely too much on radar images to chase and would like to know if there's a link that shows up-to-date images I can view before heading out? I've seen the ones on the weatherzone site and also from BSCH - but they're not up to date timewise or am i not clicking the right time!
I guess i'm after hour by hour images to enable me to locate which decent cells to go after and where i can view them?
With only 5 weeks to go till the end of the wet season, i want to get as much education i can prior to next wet season!
Mike
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Satpics are always a bit out of date by the time we get to see them. The actual scan of the Earth and the transmission times account for nearly 30 minutes I believe (not entirely sure). Those 1km VIS images from NPMOC via BSCH are as up to date as you can get. The time stamp is the time in UTC that the satellite commenced the scan at the north of the Northern Hemisphere.
Eg - 23:33UTC is the 00 UTC image for Australia as it actually closer to 00z that the satellite is 'looking' at Australia. To get a 00z satpic at 10.14am EST is as fast as we've ever been able to get them.
I guess the data is about 30 mins old by the time we can view it.
MB